According to the oxford English dictionary, the term weathering summarizes “the change in the rock in contact with the atmosphere, with water and with energy conversions, with radiation and in interaction with the first life.
To both elementary school and advanced learning, weathering is simply the gradual disintegration of rocks to form the soil.
There are different types of rock weathering and various agents responsible for the weathering of rocks, however, the three common types of weathering of rocks are the following.
- Physical weathering
- Biogenic weathering
- Chemical weathering
These types of weathering of rocks provide the basis for processes that rearrange soil formation and release rock-derived (lithogenic) nutrients.
What does Physical Weathering mean?
Physical weathering is simply the disintegration of rock by physical factors such as water, wind and others, including human and animal activities.
During physical weathering of rock, the parent rock is broken up by the release of forces that split the rock. This leads to an increase in the specific surface area of the particles.
Typical physical weathering process types are the following:
- Temperature weathering
- Frost cracking
- Salt blasting
- Temperature Weathering (Insulation Weathering)
Temperature weathering is caused by temperature changes (daily and seasonally) and changes in solar radiation, says chaktty.
The expansion and contraction (due to heating and cooling) creates stresses in the rock or mineral, then Cracks and gaps appear in the rock and split.
Frost Cracking (Cracks)
In cold climates, water penetrates cracks in the ground (for example, it can be caused by erosion of the soil), which freezes and expands (by about 9%) during frost.
The rock is then further broken down into its individual minerals.
Salt Blasting
In arid climates for example, salt cracking occurs instead of frost cracking.
The crystallization of salts dissolved in water through evaporation leads to an explosive effect.
Biogenic Weathering
According to farmpally, Biogenic weathering occurs through the explosive effect of plant roots, with tree roots in particular exerting enormous pressure on the rock above the topmost part of the soil.
Chemical Weathering
Chemical weathering causes a (partial) chemical transformation and alteration of the rock.
It comes about through interactions between the minerals in the rock and water, air, aqueous solutions of acids and organic compounds and it is favored by physical weathering.
Accordingly, chemical weathering process types include the following
Solution weathering including carbonic acid weathering
- hydrolysis (silicate weathering)
- oxidation weathering
- solution weathering
It primarily affects easily water-soluble rocks such as gypsum (CaSO 4 * 2 H 2 O).
Acid input into the soil can occur through natural processes such as carbonic acid formation or human activities such as fertilization, says farmpally scientist.
Hydrolysis
During hydrolysis, easily soluble components such as salts are dissolved in water.
The ions in the water attack the minerals. As a result, there is an exchange of ions of the mineral crystal on the surface. Especially silicates (e.g. feldspar, mica, etc.) are affected.
Oxidation Weathering
The addition of oxygen and OH groups causes a change in the crystal lattice.
This makes the rock more susceptible to further forms of weathering.
Oxidation weathering often causes a color change. For example, iron (Fe) is colored brown
